From the German publication DE-OS No. 30 24 389, there is known an arrangement for aligning a web of fabric and including a pair of tensioning blocks arranged parallel to each other and being engageable with a napless or loopless zone of the fabric at opposing sides of the zone. When being in the lowered position, the tensioning blocks stretch the fabric so as to align the latter for an associated crosscutter which cuts the web of fabric transversely to the conveying direction of fabric. The conveyor on which the web of fabric is transported operates in an intermittent manner which means that each time a napless zone is located beneath the tensioning blocks, the conveyor is stopped and these blocks are lowered to act on the fabric. When lowered onto the fabric, each tensioning block will lie against the edge of the respective nap zone. The blocks are then moved apart to stretch the napless zone and align the latter to allow an accurate separating line obtained by the associated crosscutter. Each of the tensioning blocks includes a plurality of segments arranged side by side and provided with cutouts of which at least one is manually adjustable for allowing, e.g., a longitudinal hem or border portion to pass the block and to be prevented from interfering with the tensioning and aligning step of the fabric i.e. the napless zone of the fabric.
When the blocks are lowered and provide a tensioning of the napless zone, the cross cutting device cuts along the center line of the napless zone to produce pieces of fabric, like towels of equal length. It is obvious that the tensioning blocks must be adjusted exactly symmetrically with respect to the cross cutting device in order to provide a separating line exactly centered along the napless zone.
Like tensioning blocks are known from the French Pat. No. 13 74 528.
The tensioning blocks described in the prior art have, however, the disadvantage that the cutouts for the hem or border portion of the fabric must continuously be adjusted to the flow or pattern of the hem portion since the fabric when transported to the crosscutter will not be provided with longitudinal hems exactly parallel to the conveying direction i.e. the longitudinal hem portion will rather have a somewhat wavelike pattern. Consequently, the adjustment of the cutouts for the hem portion requires a cumbersome manual work which is undesired with respect to an economical operation.
Moreover, it has been shown that the segments of the tensioning block tend to slide with their respective edge on or over the nap zone of the fabric so that the alignment and stretching of the napless zone is considerably impaired.